Benz{8 c{9 fluoran compounds and recording sheet containing the same

ABSTRACT

Novel benz(c)fluoran compounds such as 2-amino-8dimethylaminobenz(c)fluoran and N,N&#39;&#39;-o-xylylene-bis-(2-amino-8dimethylbenz(c)fluoran), which are useful as a coloring material for record material systems, such as pressure-sensitive copying paper or heat-sensitive copying paper, wherein colored images formed by an electron-donor-acceptor color-forming reaction between coloring material and acidic material.

United States Patent [191 Akamatsu et al.

Related US. Application Data Continuation of Ser. No. l88,529, Oct. 12, 1971', abandoned.

Foreign Application Priority Data Oct. 13, 1970 Japan 45-90245 Nov. 4, 1970 Japan 45-97426 Dec. 25, 1970 Japan 45-129018 Dec. 26, 1970 Japan 45-130391 Dec.9, 1975 [52] 11.8. C1. 260/335; 117/362; 117/368 [51] Int. GL C071) 407/04 [58] Field Of Search 260/335 [56] References Cited UNITED STATES PATENTS 1,194,380 8/1916 Hagenbach 260/335 3,501,331 3/1970 Kimura et'al. 260/335 3,824,119 7/1974 Terayama et al. 260/335 Primary Examiner-Norma S. Milestone Attorney, Agent, or FirmStevens, Davis, Miller & Mosher [57] ABSTRACT Novel benz[c]iluoran compounds such as 2-amino-8-.

dimethylaminobenz[c]fluoran and N,N'-o-xy1ylenebis-(2-amino-8-dimethylbenz[c]fluoran), which are useful as a coloring material for record material systems, such as pressure-sensitive copying paper or heatsensitive copying paper, wherein colored images formed by an electron-donoracceptor color-forming reaction between coloring material and acidic material.

5 Claims, No Drawings BENZ[C]FLUORAN COMPOUNDS AND RECORDING SHEET CONTAINING THE SAME This is a continuation, of application Ser. No. 188,529, filed Oct. 12, 1971 and now abandoned.

This invention relates to chromogenic compounds for use in recording sheet which develops color images by an electron donor-acceptor color-forming reaction between chromogenic material and acidic material which react upon contact to produce a color.

More particularly, the present invention relates to novel benz[c]fluorans represented by the following general formulas (l) and (H), which have never been disclosed in prior art references, methods for the preparation thereof and recording sheet containing the same as chromogenic materials.

wherein Y and Y each represent hydrogen, a lower alkyl, a lower alkoxy, a halogen atom, amino, an amino substituted by at least one lower alkyl group or nitro; Z stands for hydrogen, a lower alkyl, halogen, a lower alkoxy, nitro, amino, an amino substituted by at least one lower alkyl group, or a group of the formula,

(wherein R and R each represent hydrogen, a lower alkyl, phenyl, halophenyl, methoxyphenyl or nitrophey m is an integer of 1 to 4; A represents benzene or naphthalene nucleus and Q stands for a lower alkylene, a lower alkenylene, a lower alkynylene, or a group of -CH CH- 1' IR v R 17 R 18 Twi n l7 15 R 18 -(|!H o gm- -ca 3 on- I I 7 11 R R -1e -CIH'Q/ cu em I 4 cu ca Q en- R R -(|2H CH CH CH- or I R R IH 0 c 0 m- R R v 17 R15 R16 18 (wherein R and R each represent hydrogen atom, a lower alkyl, a lower alkoxy or a halogen; and R and R each represent hydrogen, a lower alkyl or phenyl); R and R each signify hydrogen, a lower alkyl, a lower alkoxyalkyl, a lower haloalkyl or unsubstituted or lower alkyl-, lower alkoxy-, haloor nitro-substituted benzyl group; and R and R each signify hydrogen, a lower alkyl, a lower alkoxyalkyl, a lower hydroxyalkyl, a lower haloalkyl, a lower cyanoalkyl, carbamoyl, a lower alkenyl, a lower alkynyl or a group of Woe R9 "lower alkoxy, a halogen, or nitro; and R stands for hydrogen, a lower alkyl, benzyl or phenyl).

Throughout the present specification, the term lower as is seen in lower alkyl group indicates that (III) The pressure-sensitive copying paper is usually prepared by coating a back side of one sheet of paper with a color precursor such as a leucoauramine or a fluoran, and coating a surface of another sheet of paper with an acidic electron-acceptor substance such as kaolin, bentonite, activated clay, acid clay, aluminum silicate, attapulgite, metal oxides, metal chlorides, metal sulfates,

the number of carbon atoms is from 1 to 4. organic acids such as phenols, aliphatic acids or tannic In the present specification, the present benz[c]fluoacid, or phenolic resins such as p-phenyl-phenol-forrans are named and the position substituted in the maldehyde resin, p-cyclohexylphenol-formaldehyde benz[c]fluoran nucleus are numbered as follows: resin, etc. The pressure-sensitive copying paper is used by placing the coated papers upon one another so that the back side of the first paper may be faced to the surface of the second paper, and the back side of the second paper to the surface of the third paper and so on. By applying pressure or impact to the papers by means of a pencil, a ball-point pen or a typewriter on the first paper, the material on the back side and the electronacceptor substances on the surface of the papers are brought into contact with each other, whereby the colorless pressure-sensitive material moves to the electron-acceptor layer and undergoes color development and therefore colored images can be obtained. 2-(N-methyl-3-methyl-5 '-chloro-benzylamino)-8-di- The compound (III) has defects that, when used as methylamino-benz[c]fluoran color precursor for pressure-sensitive copying paper, it

014% 0 n CH3 CH}/ 01 Cl 3 NH 0o 0 OCH} N,N'-(p,p-biphenylene)-bis(2-amino-3-chloro-8- stains capsules in undesired red color because it is dimethylamino-4'-methoxybenz[c]fluoran) slightly soluble in water or slightly acidic or alkaline So far oil carbon paper was used for making out docat umems and Slips Office Work materials It has draw- Further, it has a relatively high vapor pressure so that backs that it is to stain clothes and hands and it is it tends to vaporize from the capsules to form ghost imtroublesome to insert the oil carbon paper between documents and slips.

In order to eliminate the inefficiencies and defects of the oil carbon paper, pressure-sensitive copying paper or noncarbon paper, which is economic and handy, has recently made its debut in place of the oil carbon paper complying with demand for speed-up of office works.

Heretofore, leucoauramines, leucomethyleneblues, phthalides and fluorans are well known as color precursors. They are colorless or nearly colorless compounds, which may change to a certain coloring matter when they are brought into contact with acidic electronacceptor as explained below.

For example, Z-methyl-6-diethylamino-fluoran having the following formula (III) is one of the well-known color precursors which are colorless compounds under ordinary condition but change to red coloring matters by opening their lactone ring when they are brought into contact with acidic electron-acceptor.

ages which contaminate regular images on the pressure-sensitive copying paper and to cause the images to disappear on the paper during storage for a long period of time.

The present invention has technical advance over prior arts in the following points:

1. These fluoran compounds represented by the general formulas (I) and (II) are colorless and stable in air at ordinary temperature, but the compounds (I) and (II) change in color from white to red, blue, green or black when they are brought into contact with an acidic electron-acceptor explained in detail above.

2. These fluoran compounds (I) and (11) show all sorts of dark colors, for example, deep red, dark green,

dark blue-green, dark greenish black, or black according to the number, kind and position of substituents.

of substituents. The present benz[c]fluoran compounds have almost the same color developing speed and the pressure-sensitive copying paper obtained by mixing the present benz[c]fluoran compounds shows no lag of the color developing time and changes the color of the image.

It is also possible to use the said compounds together with other color precursors such as C.V.L. (crystal violet lactone), B.L.M.B. (benzoyl leucomethyleneblue) or 2-methyl-6-diethylaminofluoran, etc. to obtain a special color such as blue-black or black image on the paper without spoiling the other color precursors. These are significant features of the present invention.

3. These benz[c]fluoran compounds are Well soluble under colorless condition in a non-volatile non-polar solvent used for preparing a recording sheet. Examples of the non-polar solvent are as follows:

Chlorinated benzenes such as trichlorobenzenes and tetrachlorobenzenes; chlorinated biphenyls such as dichlorodiphenyls, trichlorodiphenyls, and tetrachlorodiphenyls; alkylated benzenes; alkylated naphthalenes such as dimethylnaphthalene and dipropylnaphthalene; mineral oil; paraffin oil; olive oil; and tricresyl phosphate, etc.

Such good solubility in the above solvents is probably caused by the naphthalene ring in the benz[c]fluoran nucleus represented by the general formulas (I) and (II). Good solubility particularly in the aromatic solvents makes it easy to prepare the recording sheet and to obtain a deep image on the paper.

4. The present fluoran compounds have no solubility and good stability in water, acids or alkalis. For example, Z-dibenzylamino-8-diethylamino-benz[c]fluoran can be boiled with an alkali solution without being destroyed.

S. The present benz[clfluoran compounds have good fastnesses to light, moisture and sublimation.

the obtained deep image on this recording sheet does not disappear or change in color by moisture or droplets of water, or by exposure to sun-light or by heating.

The recording sheet prepared with use of the present benz[c]fluoran compound endures storage for a long period of time without the disappearance of the image on the documents and slips.

6. The present fluoran compounds have high colordeveloping speed. Such color formation occurs just at once when the fluoran compounds in the form of crystals or a solution in the above-cited solvents are brought into contact with the acidic electron-acceptor. Then, the recording sheet prepared with use of the present benz[c]fluoran compounds gives vivid deep images on the paper at the moment when a pressure or impact is applied onto the paper by means of a pencil, a ball-point pen or a typewriter.

7. The images on the recording sheet prepared with a mixture of the present benz[c]fluoran compounds do not change in color owing to the same color-developing speeds caused by the same benz[c]fluoran nucleus. The present benz[c]fluoran compounds represented by the general formulas (I) and (II) may be prepared by the following three methods.

In the presence of a dehydrating agent, benz-[clfluorans (I) and (II) can be prepared by reacting a 0-(2- hydroxy-4-aminobenzoyl)-benzoic acid represented by the formula,

N GO 2 COOK wherein R R Z and m are as defined above, with a compound represented by the formulas,

wherein R R Y Y A and Q are as defined above and R represents hydrogen atom or a lower alkyl group, to obtain a 11-(o-carboxyphenyl)-2,8-diaminoxanthohydrol represented by the formulas,

R on DOOR wherein R,, R R R Y Y Q, A, Z and m are as defined above, and by ring-closing the resultant.

The reaction may be effected at a temperature of 30 to 300C for several hours 3r sometimes for a few days in the presence of a dehydrating-condensing agent. Examples of the dehydrating-condensing agent include sulfuric acid; phosphorus pentoxide; phosphoric acid; polyphosphoric acid; anhydrous metal halides such as anhydrous tin chloride or bromide, anhydrous zinc chloride or bromide, anhydrous aluminum chloride or bromide, anhydrous ferric chloride or bromide; phosphoric pentachloride or bromide; phosphorous trichloride or bromide, and anhydrous hydrogen chloride or fluoride.

If necessary, carbon disulfide, chlorinated benzenes, or nitrobenzenes are used as a solvent for the reaction.

The resulting xanthohydrol is converted to the fluoran compound represented by the formula (I) or (II) by closing the ring.

After the reaction is over, the reaction mixture is poured into ice or water to separate solid, and if desired, the mixture is neutralized with a solution of an alkali such as caustic soda, potassium hydroxide and the like thereby to obtain the xanthohydrol.

In order to convert the resulting xanthohydrol to the fluoran compound represented by the formula (I) or (II) by closing the ring, the xanthohydrol may be dissolved and heated in a solvent and then the mixture may be cooled or concentrated to obtain the fluoran compound (I) or (II) as white crystals.

wherein R R R R Y Z and m are as defined above.

wherein R R R A, Y Y Q, Z and m are as defined above.

The cyclization is often facilitated by the addition of an aliphatic amine such as dimethylamine, trimethylamine, diethylamine, triethylamine, etc.; an aliphatic aminoalcohol such as ethanolamine, propanolamine, etc.; or a heterocyclic basic substance such as pyridine, picoline, etc.

White crystals, which separate on heating and cooling in any one of these cyclization solvents or a mixture thereof, are filtered and washed with a nonpolar solvent such as cyclohexane, n-hexane, diethyl ether to obtain a colorless compound (I). In case of a compound having a stable lactone ring, white crystals are often obtained merely by neutralizing a hydrochloric acid or sulfuric acid solution thereof with caustic soda, potassium hydroxide, etc.

9 10 The second method is similar to the first method. The third method is accomplished by the use of a Thus, a 2-(4-amino-l '-hydroxy-2-naphthoyl)-benzoic fluoran compound prepared by the first or second acid represented by the formula, methods. Thus, a 2-aminofluoran represented by the formulas, 0H coon m R R wherein R R Y Z and m are as defined above, may 1 be reacted with a n-aminophenol at a proper reaction temperature in the presence of a dehydrating agent as a, explained above to obtain a benz[c]fluoran compound represented by the general formula (I).

The reaction proceeds as follows: or

wherein R R R Y A, Z and m are as defined above, which has at least one hydrogen atom in the amino substituent at 2-position of the benz[c]fluoran nucleus is treated with an alkylating agent, an acylating agent or a sulfonylating agent as explained below in the presence or absence of a dehydrating agent or a dehydrohalogenating agent. The reaction is properly carried out at 0 200C for several hours or sometimes for a few days, if desired, in the presence of a solvent such as benzene, toluene, xylene, chloroform, 1,2-dichloroe- Where! 1, 2 3, 4 1, Z and m are as definfid thane, ether, dioxane, N,N-dimethylformamide, diabove. The purification procedure after the reaction is methylsulfoxide, alcohols, etc. the same as that in the first method. The reaction proceeds as follows;

R X- R 2 R411 0 3 3;

1 4 0 co l wherein R R R R Y Y Z, m, A and Q are as defined above and X and X each signify a residue of the alkylating, acylating or sulfonylating agent such as halogen atom, hydroxy group, S0 1 0 etc.

Examples of the acylating, alkylating and sulfonylating agents which may be used in the above-mentioned reaction include:

1. Acetic anhydride Propionic anhydride Butyric anhydride Propiolic anhydride Crotonic anhydride Benzoic anhydride m-Chlorobenzoic anhydride o-Chlorobenzoic anhydride 7 m-Nitrobenzoic anhydride p-Bromobenzoic anhydride o-Bromobenzoic anhydride m-Methylbenzoic anhydride p-Methoxybenzoic anhydride o-Methoxybenzoic anhydride 2. Acetyl chloride Propionyl chloride Acryloyl chloride Methacryloyl chloride Crotonoyl chloride Acetyl bromide Butyryl bromide Propiolvl bromide Crotonoyl bromide Benzoyl chloride m-Chlorobenzoyl chloride p-Nitrobenzoyl chloride o-Nitrobenzoyl chloride m-Bromobenzoyl chloride p-Methylbenzoyl chloride o-Methylbenzoyl chloride m-Methoxybenzoyl chloride Benzoyl bromide p-Chlorobenzoyl bromide o-Chlorobenzoyl bromide m-Nitrobenzoyl bromide p-Bromobenzoyl bromide o-Bromobenzoyl bromide m-Methylbenzoyl bromide p-Methoxybenzoyl bromide o-Methoxybenzoyl bromide Also, as the alkylating agent, the following compounds are preferable.

3. Esters:

Dimethyl sulfate Diethyl sulfate Dipropyl sulfate Trimethyl phoshate Triethyl phosphate Methyl benzensulfonate Ethyl benzenesulfonate Methyl p-toluenesulfonate Propyl p-toluenesulfonate Methoxyethyl p-toluenesulfonate Methyl methanesulfonate Propyl methanesulfonate 4. Lower alkyl halides: Methyl chloride Methyl bromide Ethyl bromide Propyl chloride Butyl chloride 5. Benzyl halides:

Benzyl chloride m-Nitrobenzyl chloride p-Chlorobenzyl chloride o-Chlorobenzyl chloride m-Bromobenzyl chloride p-Methylbenzyl chloride o-Methylbenzyl chloride m-Methoxybenzyl chloride Benzyl bromide p-Nitrobenzyl bromide o-Nitrobenzyl bromide m-Chlorobenzyl bromide p-Bromobenzyl bromide o-Bromobenzyl bromide m-Methylbenzyl bromide p-methoxybenzyl bromide o-Methoxybenzyl bromide 13 6. Allyl halides:

Allyl chloride 2-Methylallyl chloride Z-ethylallyl chloride Z-Butenyl chloride Cinnamyl chloride 7. Propargyl halide derivatives:

Propargyl chloride Z-Butynyl chloride 2-Pentynyl chloride Z-Pentynyl bromide 3-Phenyl-2-propynyl bromide 8. Dihalides:

o-Xylylene dichloride m-Xylylene dichloride p-Xylylene dichloride 4,5-Dimethyl-o-xylylene dichloride 3,6-Dimethyl-o-xylylene chloride 4-Methyl-m-xylylene dichloride 2,5Dimethyl-m-xylylene dichloride 4,6-Dimethyl-m-xylylene dichloride 4-l-lydroxy-5-methyl-m-xylylene dichloride Z-Hydroxy-5-methyl-m-xylylene dichloride 4-Bromo-6-methoxy-m-xylylene dichloride 2-Bromo5-methyl-p-xylylene dichloride 2,5-Dimethoxy-p-xylylene dichloride 4,4'-Bis-chloromethyldiphenyl 3 ,3 -Dimethyl-4,4 -bis-chlorodiphenyl 4,4'-Bis-chloromethyldiphenylmethane 3 ,3 '-Dimethoxy-4,4 '-bis-chloromethyldiphenylmethane 4,4'-Bis-chloromethyldiphenylethane 3 ,3 -Dimethoxy-4,4 -bis-chloromethyldiphenylethane 4,4'-Bis-chloromethyldiphenylether 3 ,3 -Dimethyl-4,4 -bis-chloromethyldiphenylether 4,4-Bis-chloromethylstilbene 3 ,3 -Dimethyl-4,4 '-bis-chloromethylstilbene 3 ,3 '-Dimethoxy-4,4 -bis-chloromethylstilbene Z-Butenylene dichloride l,4-Dimethyl-2-butenylene dichloride l-Methyl-2butenylene dichloride l-Ethyl-Z-butenylene dichloride 2-Butynylene dichloride l-Methyl-Z-butynylene dichloride o-Xylylene dibromide m'Xylylene dibromide p-Xylylene dibromide 4,5-Dimethyl-o-xylylene dibromide 4-Methyl-m-xylylene dibromide 2,5-Dimethyl-m-xylylene dibromide 4-Methoxy-m-xylylene dibromide 4-Hydroxy-S-methyl-m-xylylene dibromide 4-Chloro-6-methoxy-m-xylylene dibromide 2,5-Dimethyl-p-xylylene dibromide 2,5-Dimethoxy-p-xylylene dibromide 2-Bromo-5-methyl-p-xylylene dibromide 4,4-Bis-bromomethyldiphenyl 3 ,3 '-Dimethyl-4,4 -bis-bromoethyldiphenyl 3,3-Dimethoxy-4,4-bis-bromoethyldiphenyl 4,4'-Bis-bromoethyldiphenylmethane 3 ,3 -Dimethoxy-4,4-bis-bromomethyldiphenylmethane 4,4-Bis-bromomethyldiphenylethane 3 ,3 '-Dimethyl-4,4 '-bis-bromoethyldiphenylethane 3,3'-Dimethoxy-4,4'-bis-bromomethyldiphenylethane 4,4'-Bis-bromomethyldiphenylether 14 3 ,3 '-Dimethoxy-4,4 '-bis-bromomethyldiphenyleth er 4,4-Bis-bromomethylstilbene 3 ,3+-Dimethyl-4,4 -bis-br0momethylstilbene Z-Butenylene dibromide l,4-Dimethyl-2-butenylene dibromide l-Methyl-2-butenylene dibromide Z-Butynylene dibromide l-Methyl-Z-butynylene dibromide l,4-Dimethyl-2-butynylene dibormide 2,4-l-lexadienylene dichloride 2,4-Hexadienylerie dibromide p-Bromomethylbenzyl chloride 9. Alcohols: a,a'-Dihydroxy-o-xylene a,oz'-Dihydroxy-m-xylene a,a'-Dihydroxy-p-xylene 01,01-Dihydroxy-4-methyl-m-xylene a,a'-Dihydroxy-2,5-dimethyl-m-xylene 01,01-Dihydroxy-4-methoxy-m-xylene 4,4'-Bis-hydroxymethyldiphenyl 4,4'-Bis-hydroxymethyldiphenylmethane 4,4'-Bis-hydroxymethyldiphenylethane 4,4'-Bis-hydroxymethylstilbene l ,4-Dihydroxy-2-butene l ,4-Dihydroxy-2-butyne and the like dihydroxy compounds obtained by replacing halogen in the dihalides as shown in (8) above by hydroxy group 10. Ethers:

a,a-Dimethoxy-o-xylene a,a'-Dimethoxy-m-xylene a,a'-Diethoxy-p-xylene and the like ether compounds obtained by replacing halogen in the dihalides as shown in (8) above by alkyl ether group and bromides thereof such as, for example,

Methanesulfonyl bromide Ethanesulfonyl bromide Benzenesulfonyl bromide p-Toluenesulfonyl bromide p-Chlorobenzenesulfonyl bromide p-Nitrobenzenesulfonyl bromide p-Methoxybenzenesulfonyl bromide As the dehydrohalogenating agent,

Sodium hydrogencarbonate Potassium hydrogencarbonate Sodium carbonate Potassium carbonate 15 Sodium acetate Potassium acetate and Caustic soda may be used. Also, if circumstances permit, the basic 5 substance used in the ring-closure, may be used.

As the solvent in the third method, aromatic hydro carbon solvents such as benzene, xylene, etc.; halogenated aliphatic hydrocarbon solvents such as chloroform, bromoform, methylchloroform, etc.; halogenated aromatic hydrocarbon solvents such as chlorobenzene, bromobenzene, dichlorobenzenes, etc.; alcohol solvents such as methanol, ethanol, propanol, etc.; ether solvents such as diethyl ether, dimethylene glycol, dimethyl ether, diethylene glycol, etc.; sulfoxide solvents such as dimethyl sulfoxide, diethyl sulfoxide, etc.; and amide solvents such as N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone may be used.

Specific examples of the compounds of the general formulas (l) and (II) produced by the above-mentioned methods according to the present invention which show excellent resistance to water, good fastness to light and rapid color developing speed are as follows. Shade on silica gel after development for each compound is also shown below.

Shade after Compound development Dark reddish brown Dark reddish blue 2,8-Diarnino-benz[ c lfluoran 2-Amino-S-ethylamino-bcnzlc]- Z-Dimethylamino-8-diethylamino Dark reddish violet benzl c]flu0ran Z-Benzylamino-8-dimethylaminobenz[ c lfluoran 2-( 4'-Nitrobenzylarnin0 )-8-diethylamino-benzlclfluoran Greenish black Greenish black Z-Dibenzylamino-8 dimethylamino- Dark red benz[c]fluoran Z-Dibenzylamino-8-diethylamino- Dark red benz[c]fluoran Z-Dibenzylamino-S-methylamino- Dark red benz[c]fluoran 2-(4-Chlorobenzylamino )-8-propyl- Greenish black amino-benz c lfluoran 2-( 4'-Methylbenzylamino )-8-dimethylamino-benz c]fluoran 2-Allylamino-8-ethylaminoben7.[c]fluoran Z-Propargylamino-8methylamino- Greenish black Greenish black Greenish black benz[c]fluoran Z-Diallylamino-8-ethylamino Dark red benz[c]fluoran Z-Diallylamino-S-dimethylamino- Dark red benz[c]fluoran Z-DipropargylaminoS-dimethylamino- Dark red 2 Cinnamylamino-8-propylamino- Greenish black benz[c]fluoran 2-Dicinnamylamino-S-dimethylamino- Dark red benz[c]fluoran 2-Dimethallylamino-8-diethylamino- Dark red benz[c]fluoran Z-Dicrotylamino-8-diethylamino- Dark red benz[c]fluoran Z-Acetylamino-8-dimethylamino- Dark red benzlclfluoran 2-N-Acetyl-N-methylamino 8- Dark red diethylamino-benz[ clfluoran LII -contmued V Shade after Compound development 2-N-Acetyl-N-allylamino-l- Dark red diethylamino-benz[clfluoran 2-N-(4'-Chlorohenzoyl)-umino-S- Dark red dipropylumino-benz[cll'luoran 2-N-Cinnamoylamino8-dipropylamino- Dark red benz[c]fluoran 2-(N-Acryloyl-N-ethylamino)-8-di- Dark red methylamino-benzlclfluornn 2-(N Acetyl-Ncinnamylamino)-8- Dark red dimethylamino-benz[c]fluorun N,N'-o-Xylylenc-bis(2amino-8- Green dimethylaminobenzlc ]fluoran) N,N'-m-Xylylene-bis(2-amino-8- Green dipropylaminobenzl c]fluoran) N,N'-( 3 -Methyl-o-xylylene )-bis- (Z-methanesulfonylamino-8-diethylaminobenzic ]fluoran) N,N 4,4-Biphenylenedimethylene Green bis-( 2-amino-8-dimethylamino- Dark green Dark red N,N'-(4,4'-Biphenylenedimethylene)- Dark red bis-( 2-benzylamino-8-dimethylamino-benz[c]fluoran) N,N'-(4,4-Biphenylenedimethylene)- Dark red bis 2-o-nitrobenzoylamino-8- dimethylamino-benz[ c ]fluoran) N,N '-Ethylene-( di-pphenylene- Green dimethylene)-bis-( 2-amino-8dimethylaminobenz[c ]fluoran) N,N'-Ethylene-bis-(3.3'-dimcthyl- Green p-phenylenebis-(2-amino-8- diethylamino benzlc ]fluoran) N.N'-Methylene-(di-pphenylene- Green dimethylene)-bis-(2-amino-8- dimethylamino-benzlc ]fluoran) Dark red Green Mon (cs n 0 NH NH 0 l I CH 0 o 2 2 co N,N -Oxy-( di-p-phenylenedimethylene Dark red bis (2 acetylamino-8-dibenzylaminobenzlclfluoran) N,N'-Oxy-( di-p-phenylene- Dark red dimethylene )-bis-( 2-bromomelhylamino-8-dimethylamino-benz[clfluoran) N,N'-Vinylene-(di-p-phenylene- Green dimethylene )-bis-( 2-amino-8- dimethylamino-benz[c]fluoran) NH NH 0 I I (I) l ca cn=cu Q4; co 2 2 co N,N'-Vinylene-(di-p-phenylene- Dark red dimethylene )-bis-( Z-cinnamylamino-S-dimethylamino-benz[c]fluoran) N,N'-2-Butenylene-bis-(2-amino-8- Green dimethylamino-benz[c]fluoran) (CH N 0 92 NE NH O I CH CH=-CH-Cl'l co 2 2 co N,N-2Butenylene-bis-(2-amino-8- Green di-tert.-butylamino-benz[c]fluoran) N,N'2Butenylene-bis-(2-amino-8- Green diethylamino-3'-chloro-benz[c]fluoran) N,N'-2-butynylene-bis-(2-amino-8 Green dirnethylamino-benz[c]fluoran) (cu u o u(ca NE NH 1) I I 0 CH CECCH co 2 2 (i0 N,N'-2',5'-Dimethoxy-p-Xylylene-bis- Bluish green- (2-amino-6-dimethylaminofluoran) black Green black N,N'-o-Xylylene-bis-( 2-m-chlorobenzylamino-6-dimethylamino- 3 '-chlorofluoran) N,N'-m-Xylylene-bis-( Z-nicotyl- Dark red amino-o-diethylaminofluoran) N.N-( 3,3-Dimethoxy-4,4-bi- Bluish greenblack phenylylenedimethylene )-bis- (2-amino-6-diethylaminofluoran) N,N"Methylene-(di-p-phenylene)- (dimethylene )-bis 2-benzylamino- G-dimethylaminofluoran) N,N'-Ethylene-( di-P-phenylene (dimelhylene)-bis-(2-p-nitrophenylamino-6-diethylaminofluoran) N,N"Oxy-(di-p-phenylene) (dimethylene)- bis-( Z-amino-dimethylaminofluoran) N,N'-Vinylene-( di-pphenylene (dimelhylene )-bis-( 2-allylamino-6- diethylaminofluoran) N,N '-2-Butenylene-bis-( Z-methylamino- -dimethylaminofluoran) N,N '-2-Butenylene-bis( Z-p-meth oxyphenylarnino-6-dimethylaminofluoran) N,N'-2-Butynylene-bis-( 2-propargylamino-G-dimethylaminofluoran) N,N'-Trimethylene-bis-( Z-methylamino- -dimethylaminofluoran) Greenish black Greenish black Bluish greenblack Greenish black Greenish black Greenish black Greenish black Green As used on markforming systems, marking in desired areas on support webs or sheets may be accomplished by effecting localized reactive contact between the chromogenic material and the acidic material on or in such web or sheet, such chromogenic material being brought thereto by transfer, or already present therein, the reactive contact forming a clear coloration in the intended image-marking areas.

There have already been known several types of recording system utilizing an electron donor-acceptor color-forming reaction between chromogenic material and acidic material. 5

The pressure-sensitive recording system generally comprise color-forming components on and/or within one or more sheet supports, the color-forming components being isolated from one another by a pressurerupturable barrier. Where the color-forming components are disposed on separate sheets as disclosed in US. Pat. No. 2,712,507, the record material referred to as a transfer or couplet system. In such system, a solution of a chromogenic material is held in rupturable microscopic capsules coated onto one surface of a transfer sheet, while an adjacent receiving sheet is sensitized with an acidic material, i.e., an electron-acceptor. Most common acidic materials are activated acid clay and acid clays, such as attapulgite, zeolite, bentonite, kaolin and silica. Recently, monomeric phenols or acid reactant polymeric materials, such as phenolic polymers, phenol acetylene polymers, maleic acidrosin resins, have been suggested either alone or in combination with acid clays.

In the manufacturing method of such record material, for instance, a non-volatile oil containing a chromogenic material dissolved therein is protected by encapsulation with coacervate film of a water-soluble polymer. The resulting coating composition containing dispersed capsules are coated on one side of a sheet, and coating composition of said electron-acceptors is coated on the other side of the sheet. When several sheets are laid one over another and impressed with a sules chromogenic material and acidic material is applied on one side of a sheet or alternatively, a coating containing capsules is first applied on one side of a sheet and the second coating containing the electronacceptor is applied thereon. Thus, all the components are disposed on a single sheet, the record material is referred to as self-contained system and develops image color where the pressure is applied.

As a modification of pressure-sensitive marking system, Japanese Patent No. 51 1,757 (corresponds to US. Patent application Ser. No. 392,404, filed on Aug.

27, 1964) discloses a recording sheet, in which minute capsules containing liquid solvent are coated on one surface of a sheet support and both of the chromogenic material and the acidic polymer are coated on or impregnated in same sheet or other sheet in solid condition.

There is thermo-responsive record sheet as a markforming system utilizing an electron donor-acceptor color-forming reaction. For example, Japanese Pat. No. 45-14039 (corresponds to US. Pat. application Ser. No. 554,565 filed on June 1, 1966) discloses a temperature-responsive record material comprising a supporting sheet material having crystal violet lactone and a phenolic material solid at room temperature but capable of liquefying and/or vaporizing at normal thermographic temperatures, said lactone and phenolic material being further capable of producing a markforming reaction upon reactive contact.

The novel compounds of our invention are widely used for above-mentioned mark-forming systems as a colorless chromogenic compound, i.e., electron donor and gives many excellent advantages.

According to the present invention, the above-mentioned known techniques for the production of the recording sheet are utilized using the above-mentioned fluoran compounds as a coloring material alone or in admixture with various known coloring materials to obtain the recording sheet which can form red, green or black color.

Also, it is effective for improving the color forming property and fastnesses to light and moisture of developed images to use a metal or metallic compound together with the electron-acceptor.

Thus, metals or metallic compounds such as manganese, nickel, cobalt, iron, zinc, copper, cadmium, mercury, silver, platinum, etc. are effective. Specific examples of the metallic compounds include salts and acid sulfate, cobalt sulfate, zinc sulfate, nickel acetate, etc.;

basic salts such as cadmium hydroxide; and oxides such as zinc oxide. They show particularly good results.

The present invention will be further specifically explained below referring to the following examples which do, of course, not limit the scope of the present invention.

EXAMPLE 1 140 Grams of 95 sulfuric acid was charged into a four-necked flask provided with a stirrer, a thermometer and a hydrogen chloride gas absorber. A mixture of 25 g of 4-amino-lnaphthol hydrochloride and 31.3 g of o-(2'-hydroxy-4'-diethylaminobenzoyl)-benzoic acid was added for 1 hour below 25C. At that time, the hydrogen chloride gas evolved was absorbed in the absorber. After dissolution, the mixture was warmed to 25 to 30C for 5 hours. After cooling, the reaction mixture was then poured into 700 g of ice-water at 10 to 20C. The mixture was neutralized with an aqueous caustic soda solution at the same temperature.

The precipitate was filtered and washed with water. The thus obtained solid 1 l-(2'-carboxyphenyl)-2- amino-8-diethylaminobenz[c]xanthohydrol was dissolved in 400 g of chloroform and dehydrated with g of anhydrous sodium sulfate. After addition of 5 g of active charcoal, the chloroform solution was filtered while hot. The filtrate was concentrated under reduced pressure to obtain the crystals. Thus, 26 g of 2-amino- 8-diethylaminobenz[c]fluoran represented by the formula,

was obtained as white crystals in a yield of about 45%.

Melting point: 235 237C Visible spectrum A 435.5 my. and 595 m p.

(acetic acid) The resulting compound formed dark bluish green color on contacting with silica gel when used as a material for pressure-sensitive copying paper. The image having excellent fastnesses to light, moisture, sublimation and alkali were produced.

EXAMPLE 2 In the same manner as in Example 1, the following compounds were synthesized. Shade on silica gel is shown on the right hand column.

salts such as copper sulfate, ferrous sulfate, manganese Benzoyl Naphthylamine bsnzoic acid Product Shade Nli 'kicl 03 co Dark reddish black H Cool! on 2 KHZ-H01 0a co Dark purplish blue 0H CHZNH COOH Dark purplish blue Bluish black Bluish black Dark groan Gz'eenish b] acK.

'eenish bIa K Lark red Dari. r'eddish violet r o CH CH -hd I COOH co: i

coon

Mi -H01 Mus cs on 2 3 2 1 no M05 l/ Dark reddish I violet (ca N N CH 3 2 coon 3 2 9' N(CH C-l co Dark reddish CELCH violet H1 2 coon women a b C C NHCHZ .1.3

\ Greenisr. black ca cs na coon ocii no NH I CELCH=CHCH COOH Green COOH Green EXAMPLE 3 4 8.72 Grams of 2-amino-8-diethylaminobenz[c]-fluowas obtained as white crystals. Yield: 80%. The product was recrystallized from a benzene-cyclohexane mixture. The resulting crystals showed a melting point of 201 203C and a visible spectrum A 433.0

5 mp and 578.0 mp. (acetic acid). This compound formed purplish red color on silica gel.

EXAMPLE 4 The same procedure as in Example 3 was repeated by using propargyl bromide and 2-amino-8-diethylaminobenz[c]fluoran. Thus, 2-dipropargylarnino-8-diethylaminobenz[c]fluoran represented by the formula,

(CHECCH N was obtained as white crystals having a melting point of 193 to 196C. This compound gave purplish red color on silica gel.

EXAMPLE 5 In the same manner as in Example 4, 2-diallylamino- 8-diethylaminobenz[c]fluoran represented by the formula,

was obtained from 18 g of allyl bromide and 2-amino-8- o "(a H diethylaminobenz[c]fluoran. This compound formed 9 5 2 red violet color on silica gel.

'(CH2=CHOH2) 2N o 5 EXAMPLE 6 In the same manner as in Example 4, the compounds of the following formulas were obtained. Shade on silica gel is shown in the right hand column.

Fluoren compound Product Shade CH SO OCH INCH 2 Dark rod 0 I C0 HZN 0 QCHAIH-CH Cl cu=cucn 2: Dark red co co 2 0 Men 3 2 Green black Br Br B K Q 3 (CH 0 0 (cu v 3 3 2 (unfigw 5 0 (c21 mi 05 c1 0 m 1 O 2 N V gram Dark 29 EXAMPLE 7 was obtained in a yield of 65.0%. This compound showed a melting point of 259 to 260C (decomp.) and a visible spectrum A 409 mu, 525 my, and 5 60 my. (acetic acid), and formed red color on silica gel. 30 2% EXAMPLE 8 According to the procedure similar to that of Example 7, 2-(p-toluenesulfonylamino)-8-diethylaminobenz[c]fluoran represented by the formula,

was obtained as white crystals from 13.0 g of 2*amino- 8-die thylaminobenz[c]fluoran and 8.5 g of p- 45 30 toluenesulfonyl chloride in N,N-dimethylformamide. This compound had a melting point of 221 to 225C and a visible spectrum k 428.5 mu, 521.5 my. and 557.0 my. (acetic acid).

EXAMPLE 9 In the same manner as in Example 7, N,N'-p-xylylene-bis-( 2-acetylamino-S-diethylamino[c ]fluoran) l0 represented by the formula,

was obtained from N,N'-p-xylylene-bis-(2-amino-8- diethylaminobenz[c]fluoran) represented by the formula,

and acetic anhydride. This compound formed dark purplish red color on silica gel.

EXAMPLE 10 In the same manner as in Example 7, the compounds of the following formulas were obtained. Shade on silica gel is shown in the right hand column.

Fluoran compound Product: Shad? a s 2 a u I -co) o Dark rod.

0 N(C2H4C1)2 N(C,H4C1)2 on I ,ca 011 0001 cn cir cor r Dark mt (on 1r Dar-k CHKCOCI rod.

- cont'd Continued Fluoran compound Product Shade Dark red EXAMPLE 1 l 3 A mixture of 3.6 g of 2-methylamino-6-diethylam1nofluoran represented by the formula,

and 1.05 g of p-xylylene dibromide in 30 g of N,N- dimethylformamide was maintained at 70 to 80C for 4 hours in the presence of sodium bicarbonate. The reaction mixture was then poured into 1,000 g of cold water to separate a solid which was dissolved in 200 g of benzene. The benzene solution was washed with a dilute aqueous Na CO solution and with water several times and dried over anhydrous sodium sulfate. The solution was then concentrated under reduced pressure to form white crystals which were filtered. Thus, N,N'- p-xylylene-bis-(2-methylamino-6-diethylaminofluoran) represented by the formula,

having a melting point of 168 to 169C was obtained in O a yield of 88%. This compound formed green color on silica gel.

EXAMPLE l2 N,N -p-Xylylene-( 2-amino-8-diethylamino-benz[ c fluoran) represented by the formula,

was produced as white crystals by the same method as in Example 11 from 1 1.5 g of 2-amino-8-diethylaminobenz[c]fluoran and 3.3 g of p-xylylene dibromide in N,N-dimethylformamide. Yield: 91.0%. Melting point: 210C. This compound formed green color on silica gel.

EXAMPLE 1 3 In the same manner as in Example 1 l, the following similar compounds were obtained. Shade on silica gel is shown in the right hand column.

5 The procedures for the preparation of recording sheets are illustrated by the following examples.

EXAMPLE A In 200 g of dichlorodiphenyl was dissolved 6 g of 2- (4-methylbenzylamino)-8-diethylaminobenz[c]fluoran represented by the formula,

The resulting solution was mixed vigorously at 40C with 360 g of a 1 1.0% aqueous gelatin solution to make Red image was obtained by the application of pressure by handwriting. The thus obtained red color had good fastnesses to light, water and heat.

EXAMPLE C an emulsion. To the resulting emulsion, 300 g of a lO% aqueous gum arabic solution was added. Acetic acid was added to the mixture at C with stirring to adjust the pH value to 5, and water was then added to effect the coacervation of the system, whereby oil droplets containing the above-mentioned benz[c]fluoran compound were coated by the coacervated liquid wall of a complex of gum arabic and gelatin. At 5C, the pH value of the system was further reduced to 4.4 and 5 g of 35 formalin was added to harden the wall. In order to complete microencapsulation, 10% sodium hydroxide was added to increase the pH value to 9 and the whole system was then gradually warmed to 50C. The coating composition containing the thus prepared microcapsules was applied onto paper in a conventional manner. This paper was faced to the second paper onto which active clay or a phenylphenol-formaldehyde resin had been aplied together with a binder. A dark green image was instantly formed on the second paper by applying pressure by means of a pencil. The thus obtained green image did not change in color and showed good fastnesses to light, water and heat.

EXAMPLE B According to a procedure similar to that of Example A, similar pressure-sensitive copying paper was prepared from 6 g of 2-dibenzylamino-8-diethylaminobenz[c]fluoran represented by the formula,

With a pressure of a typewriter, deep green image was obtained. The thus obtained deep green color had good resistances to light, water and heat.

EXAMPLE D In the same manner as in Example A, pressuresensitive copying paper was produced by using N,N-p-xylylene-bis-( 2-amino-8-diethylaminobenz[ c ]fluoran) represented by the formula,

as an electron donating color former and activated clay as an electron-acceptor substance. Green copied image obtained on the electron-acceptor-coated surface had good fastnesses to light and water.

EXAMPLE E Shade Bluiah green Green 

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